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Numerical study on wake characteristics of high-speed trains

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Acta Mechanica Sinica 2013年第6期29卷 811-822页

作者： Shuan-Bao Yao Zhen-Xu Sun Di-Long Guo da-wei chen Guo-wei Yang Key Laboratory for Mechanics in Fluid Solid Coupling Systems Institute of MechanicsCAS CSR Qingdao Sifang Locomotive Co.Ltd.

Intensive turbulence exists in the wakes of high speed trains, and the aerodynamic performance of the trailing car could deteriorate rapidly due to complicated features of the vortices in the wake zone. As a result, the safety and amenity of high speed trains would face a great challenge. This paper considers mainly the mechanism of vortex formation and evolution in the train flow field. A real CRH2 model is studied, with a leading car, a middle car and a trailing car included. Different running speeds and cross wind conditions are considered, and the approaches of un- steady Reynold-averaged Navier-Stokes （URANS） and de- tached eddy simulation （DES） are utilized, respectively. Re- suits reveal that DES has better capability of capturing small eddies compared to URANS. However, for large eddies, the effects of two approaches are almost the same. In conditions without cross winds, two large vortex streets stretch from the train nose and interact strongly with each other in the wake zone. With the reinforcement of the ground, a complicated wake vortex system generates and becomes strengthened as the running speed increases. However, the locations of flow separations on the train surface and the separation mechanism keep unchanged. In conditions with cross winds, three large vortices develop along the leeward side of the train, among which the weakest one has no obvious influence on the wake flow while the other two stretch to the tail of the train and combine with the helical vortices in the train wake. Thus, optimization of the aerodynamic performance of the trailing car should be aiming at reducing the intensity of the wake vortex system.

关键词： Wake flow structures URANS DES High speed trains

Numerical study on the aerodynamic performance and safe running of high-speed trains in sandstorms

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第12期12卷 971-978页

作者： Hong-bing XIONG Wen-guang YU da-wei chen Xue-ming SHAO Department of Mechanics Zhejiang University Hangzhou 310027 China National Engineering Laboratory for System Integration of High-Speed Train （South） CSR Qingdao Sifang Co. Ltd. Qingdao 266111 China

The influence of sandstorms on train aerodynamic performance and safe running was studied in response to the frequent occurrence of sandstorm weather in north *** Eulerian two-phase model in the computational fluid dynamic (CFD) software FLUENT,validated with published data,was used to solve the gas-solid multiphase flow of a sandstorm around a *** train aerodynamic performance under different sandstorm levels and no sand conditions was then *** showed that in sandstorm weather,the drag,lift,side forces and overturning moment increase by variable *** on a numerical analysis of aerodynamic characteristics,an equation of train stability was also derived using the theory of moment balance from the view of dynamics.A recommended speed limit of a train under different sandstorm levels was calculated based on the stability analysis.

关键词： High-speed train Sandstorm Gas-solid multiphase Eulerian two-phase model Aerodynamic Safety Speed limit

Unsteady simulation for a high-speed train entering a tunnel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第12期12卷 957-963页

作者： Xin-hua LI Jian DENG da-wei chen Fang-fang XIE Yao ZHENG School of Aeronautics and Astronautics Zhejiang University Hangzhou 310027 China National Engineering Laboratory for System Integration of High-Speed Train （South） CSR Qingdao Sifang Co. Ltd Qingdao 266111 China

In order to study the unsteady aerodynamics effects in railway tunnels,the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved,and the two-equation k-ε model is used in the simulation of turbulence,while the dynamic grid technique is employed for moving *** focus on obtaining the changing tendencies of the aerodynamic force of the train and the aerodynamic pressures on the tunnel wall and train surface,and discovering the relationship between the velocity of the train and the intensity of the micro pressure wave at the tunnel *** is shown that the amplitudes of the pressure changes in the tunnel and on the train surface are both approximately proportional to the square of the train speed,so are the microwave and the drag of the train.

关键词： High-speed train Aerodynamics Railway tunnel Numerical analysis

Study of electrospray ionization tandem mass spectrometry of the benzofuranone compounds

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Chinese Chemical Letters 2008年第3期19卷 324-328页

作者： Zhan Qi Niu Yu Min Sun Feng Niu Jian Han da wei chen School of Pharmacy of Shenyang Pharmaceutical University Shenyang 110016 China ShiJiaZhuang Pharnta Group NBP Pharmaceutical Co. Ltd. Shijiazhuang 052160 China Department of Pharmaceutical Engineering School of Chemical EngineeringDalian University of Technology Dalian 116000 China Department of Natural Medicines School of Pharmaceutical Sciences Peking Universio Health Science Center Beijing 10008.3 China

A detailed analysis of benzofuranone compounds under multiple tandem mass spectrometry （ESI-MS^n） conditions is reported. Element composition data of the fragment ions were obtained with the aid of comparison of the multiple tandem mass spectra of four compounds, and the structures of which are identical except for some substituted groups or epimers or cis-trans-isomers. Attempts have been made to provide rational pathways for the formation of the fragment ions from these protonated compounds. And the structure-fragmentation relationships will facilitate the characterization of the structures of other analogs.

关键词： ESI-MS^n Benzofuranones Epimer: cis-trans-Isomer

Dissection of No.13 lymph node in radical gastrectomy for gastric carcinoma

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World Journal of Gastroenterology 2008年第6期14卷 936-938页

作者： Ding-Feng Shen da-wei chen Zhi-wei Quan Ping Dong Xue-Feng Wang Hai-Zhou Xu Ming-Lin Zhao Lei chen Department of General Surgery Shanghai Xinhua Hospital School of Medicine Shanghai Jiaotong University Shanghai 200092 China

AIM: To evaluate the feasibility and safety of No. 13 lymphadenectomy in radical gastrectomy for gastric carcinoma. METHODS: Medical records of the patients undergone No. 13 lymph node dissection during D2 gastrectomy for gastric carcinoma, were reviewed from March 2003 to May 2007. RESULTS: One hundred and fifty-eight patients underwent No. 13 lymph node dissection for D2 gastric carcinoma, of them, 4 (2.53%) were found to have metastasis in No. 13 lymph node. Metastasis to No. 12 lymph node was detected in 6 patients and 4 of them had positive No. 13 lymph node. The operative morbidity except for wound infection was 15.19% (24/158), and hospital death rate was 1.27% (2/158). No obstructive jaundice caused by No. 13 lymph node metastasis after No. 13 lymph node dissection in radical gastrectomy for gastric carcinoma was detected during the follow-up study to end of January 2007. CONCLUSION: Dissection of No. 13 lymph node in D2 gastrectomy for gastric carcinoma is safe with a low morbidity and mortality rate. Further study is needed to explore its long-term effect.

关键词： Gastric carcinoma Lymphadenectomy Gastric carcinoma No. 13 lymph node

Synthesis and Characterization of a Novel Galactosylated Cholesterol

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Chinese Chemical Letters 2006年第2期17卷 173-176页

作者： Shao Ning WANG Ying Kun QIU Hui XU Yi Hui DENG da wei chen School of Pharmacy Shenyang Pharmaceutical University Shenyang 110016 School of Pharmcy Yantai University Yantai 264005 Shandong Engineering Research Center of Natural Drugs Yantal 264003

A novel galactosylated cholesterol with mono-galactoside moiety, （5-cholesten-3-yl）-4-oxo-4-[2-（lactobionylamido）ethylamido]butanoate 6 was synthesized. Its chemical structure was characterized by IR, ESI-MS, ^13C NMR, ^1H NMR. Doxorubicin entrapped in the liposomes containing 10% mol/mol 6 was rapidly accumulated in liver and mainly uptake by parenchymal cells in mice.

关键词： Galactosylated cholesterol (5-cholesten-3-yl)-4-oxo-4-[2-(lactobionylamido)ethylamido]butanoate hepatocyte-selective targeting doxorubicin.

Imprinting methylation and assisted reproductive technology

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Journal of Reproduction and Contraception 2015年第2期26卷 112-120页

作者： Yan HAO Zhi-guo ZHANG dan HAN Ping ZHOU Yun-xia CAO Zhao-lian wei Dong-mei JI Bei-li chen wei-wei ZOU da-wei chen Fu-xi ZHU Reproductive Medicine Center Department of Obstetrics and Gynecology the First Affiliated Hospital of Anhui Medical University

Assisted reproductive technology （ART） is an important treatment for infertile people of reproductive age and is also known as fertility treatment. The processes of ART involves the isolation, handling and culture of early embryos, which may result in alterations in genomic methylation at specific loci and influence the proper establishment and maintenance of genomic imprints. Recent studies have identified an increased incidence of imprinting disorders via ART. In this article, we reviewed that the ART may be prone to induction of imprinting methylation errors during embryonic development. Further studies are necessary to elucidate the safety of ART in this field.

关键词： imprinting methylation assisted reproductive technology (ART) disoder epigenetics

Therapeutic utility of human umbilical cord-derived mesenchymal stem cells-based approaches in pulmonary diseases:Recent advancements and prospects

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World Journal of Stem Cells 2024年第2期16卷 70-88页

作者： Min Meng wei-wei Zhang Shuang-Feng chen da-Rui Wang Chang-Hui Zhou Department of Central Laboratory Liaocheng People’s HospitalLiaocheng 252000Shandong ProvinceChina Department of Clinical Laboratory Liaocheng People’s HospitalLiaocheng 252000Shandong ProvinceChina

Pulmonary diseases across all ages threaten millions of people and have emerged as one of the major public health issues *** diverse disease con-ditions,the currently available approaches are focused on alleviating clinical symptoms and delaying disease progression but have not shown significant therapeutic effects in patients with lung *** umbilical cord-derived mesenchymal stem cells(UC-MSCs)isolated from the human UC have the capacity for self-renewal and multilineage ***,in recent years,these cells have been demonstrated to have unique advantages in the treatment of lung *** searched the Public Clinical Trial database and found 55 clinical trials involving UC-MSC therapy for pulmonary diseases,including coronavirus disease 2019,acute respiratory distress syndrome,bron-chopulmonary dysplasia,chronic obstructive pulmonary disease,and pulmonary *** this review,we summarize the characteristics of these registered clinical trials and relevant published results and explore in depth the challenges and opportunitiesfaced in clinical ***,the underlying mole-cular mechanisms involved in UC-MSC-based therapy for pulmonary diseases are also analyzed in *** brief,this comprehensive review and detailed analysis of these clinical trials can be expected to provide a scientific reference for future large-scale clinical application.

关键词： Pulmonary diseases Mesenchymal stem cells Human umbilical cord Cell therapy Clinical trials

Regulating ion transport behaviors toward dendrite-free potassium metal batteries:recent advances and perspectives

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Rare Metals 2024年第4期43卷 1435-1460页

作者： Lu-Kang Zhao Xuan-Wen Gao Tian-Zhen Ren da Wang da-wei Wang Zhao-Meng Liu Hong chen Wen-Bin Luo School of Metallurgy Northeastern UniversityShenyang110819China School of Chemical Engineering The University of New South WalesSydneyNSW2052Australia

With abundant potassium resources and high capacity,potassium metal batteries(PMBs)present a compelling option for the next generation of energy storage ***,PMBs suffer from an unstable anode interface caused by uncontrolled dendrite growth,which results in unsatisfactory cyclability and safety *** investigations suggest that significant progress has been made in enhancing the interfacial stability of *** various effective strategies for stabilizing interfaces can ultimately be attributed to the regulation of the sluggish ion transfer kinetics and irregular deposition,i.e.,the arrangement of ion transport behaviors at the *** modulation of ions transport rate and ions deposition directions makes it possible to obtain a dendrite-free and smooth deposition ***,the influencing factors and action mechanism of K^(+)interface transport behaviors are discussed to understand the nature of material design for constructing stable anode interfaces,including regulating the solvation and desolvation structures,accelerating K^(+)transport kinetics and controlling K^(+)deposition *** addition,the deficiencies and prospects of the research on electrolyte,separators and designed electrode involved in the manufacturing and testing and ion transport process of PMBs are *** review is expected to provide some possible directions for constructing dendrite-free interfaces in advanced PMBs-related research and offer significant insights for prospective experimental research and commercial applications.

关键词： Ion transport rate Ion transport direction Interface Potassium metal batteries Dendrites growth